Question's About Asus Strix 7.1

hello and a have a nice day to you all i have a couple of question's in my mind and hope you guys can help me im using Strix Wireless 7.1 gaming headset for a couple of weeks now and i wonder what's the charging time of this device and how to enable 7.1 sound to hear from left right and rear i only hear the sound's from front please help me thank's best regards ..